1. Field of the Invention
The present invention relates to a down-hole fluid drill assembly for boring holes in the earth. The drill assembly comprises a bit and housing that is rotated by the passage of a fluid through the assembly.
2. Description of the Prior Art
The two most widely used apparatuses for drilling bore holes in the earth are the surface mounted rotary drill and the down hole motor assembly. The rotary drilling method utilizes a string of drilling pipes that has a drill bit attached to the down hole free end. The drill string is rotated by a drive mechanism at the earth's surface, causing the drill bit to rotate. The down-hole assemblies utilize a motor that is attached proximal to the bit and rotates the bit by an electrical or hydraulic motor.
Down-hole hydraulic screw motors are well known in the art. One such device is disclosed in U.S. Pat. No. 469,840, issued to A. McDougall, which discloses a worm screw mounted to a shaft with a bit attached. The worm screw is rotated within a stationary casing by a hydraulic fluid flowing under pressure against the worm screw. This invention requires a continuous rigid pipe casing to be inserted within the bore hole.
U.S. Pat. No. 3,047,079, issued to G. D. Wepsala, Jr., discloses a floating shaft turbo drill that comprises a shaft having helical vanes attached about a portion of the shaft's length and a drill bit attached to one end. The shaft and vanes are mounted within a stationary casing. The stationary casing is attached to a hollow drill string that permits a hydraulic fluid to pass down the drill string to strike the vanes. The fluid impinging the vanes generates rotational forces in the shaft causing the bit to turn.
U.S. Pat. No. 4,646,856, issued to N. V. Dismukes and U.S. Pat. No. 4,823,889, issued to D. F. Baldenko, both disclose a shaft with a drill bit attached that is rotated within a stationary casing. The shafts are rotated by hydraulic fluid interacting with a rotor and stator assembly. Both inventions are attached to the standard rigid drill string.
U.S. Pat. No. 1,482,702, issued to C. C. Scharpenberg, discloses a turbine motor that comprises a rotatable central shaft, having a series of spaced apart power vanes attached along the length of the shaft and a drill bit attached to one end of the shaft. The shaft and vanes are mounted within a stationary shell that has a series of vertically spaced apart sets of stationary guide vanes that alternate with the power vanes. The shell is attached to a drill string permitting hydraulic fluid to pass down the drill string impinging the power vanes causing the vanes, shaft and drill bit to rotate.
U.S. Pat. No. 4,253,532, issued to B. Geczy, discloses a rotatable helicoidal rotor mounted within a cavity stator to create a positive rotation of a shaft to which a drill bit is attached. During normal operation, the stator is stationary; however, the exterior casing of the drill motor may be rotated by rotational equipment at the earth's surface when a clutch is engaged.
U.S. Pat. No. 4,406,332, issued to N. V. Dismukes, discloses a drill bit mounted to a shaft that is rotated by attached turbine blades mounted within a non-rotating flexible drill pipe. Also attached to the shaft is a propeller blade that has jet nozzles located near the propeller tips to provide additional rotative torque.
None of the prior art discloses helical vanes connected both to a shaft and to the exterior housing to which the drill bit is attached. In addition, all the prior art that is used for drilling vertical shafts into the ground disclose rigid pipe strings. The present invention utilizes a flexible hose which is much lighter than the pipe strings allowing a single person to operate the fluid drill assembly. The rotation of the housing and bit combination provides increased moment force to assist in overcoming obstacles to the drilling. In addition, the spiraling motion of the housing will help seal the walls of the bore hole to reduce the probability of cave in.